A randomised controlled trial of nasal decongestant to treat obstructive sleep apnoea in people with cervical spinal cord injury

Prevalence of central sleep apnea in people with tetraplegic spinal cord injury: a retrospective analysis of research and clinical data

STUDY OBJECTIVES

Over 80% of people with tetraplegia have sleep-disordered breathing (SDB), but whether this is predominantly obstructive or central is unclear. This study aimed to estimate the prevalence of central sleep apnea (CSA) in tetraplegia and the contributions of central, obstructive, and hypopnea respiratory events to SDB summary indices in tetraplegia.

METHODS

Research and clinical data from 606 individuals with tetraplegia and full overnight polysomnography were collated. The proportions of different respiratory event types were calculated; overall and for mild, moderate, and severe disease. The prevalence of Predominant CSA (Central Apnea Index [CAI] ≥ 5 and more central than obstructive apneas) and Any CSA (CAI ≥ 5) was estimated. Prevalence of sleep-related hypoventilation (SRH) was estimated in a clinical sub-cohort.

RESULTS

Respiratory events were primarily hypopneas (71%), followed by obstructive (23%), central (4%), and mixed apneas (2%). As severity increased, the relative contribution of hypopneas and central apneas decreased, while that of obstructive apneas increased. The prevalence of Predominant CSA and Any CSA were 4.3% (26/606) and 8.4% (51/606) respectively. Being male, on opiates and having a high tetraplegic spinal cord injury were associated with CSA. SRH was identified in 26% (26/113) of the clinical sub-cohort.

CONCLUSIONS

This is the largest study to characterize SDB in tetraplegia. It provides strong evidence that obstructive sleep apnea is the predominant SDB type; 9-18 times more prevalent than CSA. The prevalence of CSA was estimated to be 4%-8%, significantly lower than previously reported.

Overview of the Role of Pharmacological Management of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) remains a prominent disease state characterized by the recurrent collapse of the upper airway while sleeping. To date, current treatment may include continuous positive airway pressure (CPAP), lifestyle changes, behavioral modification, mandibular advancement devices, and surgical treatment. However, due to the desire for a more convenient mode of management, pharmacological treatment has been thoroughly investigated as a means for a potential alternative in OSA treatment. OSA can be distinguished into various endotypic or phenotypic classes, allowing pharmacological treatment to better target the root cause or symptoms of OSA. Some medications available for use include antidepressants, CNS stimulants, nasal decongestants, carbonic anhydrase inhibitors, and potassium channel blockers. This review will cover the findings of currently available and future study medications that could potentially play a role in OSA therapy.

Detection of Sleep-Disordered Breathing in Patients with Spinal Cord Injury Using a Smartphone

Patients with spinal cord injury (SCI) have an increased risk of sleep-disordered breathing (SDB), which can lead to serious comorbidities and impact patients’ recovery and quality of life. However, sleep tests are rarely performed on SCI patients, given their multiple health needs and the cost and complexity of diagnostic equipment. The objective of this study was to use a novel smartphone system as a simple non-invasive tool to monitor SDB in SCI patients. We recorded pulse oximetry, acoustic, and accelerometer data using a smartphone during overnight tests in 19 SCI patients and 19 able-bodied controls. Then, we analyzed these signals with automatic algorithms to detect desaturation, apnea, and hypopnea events and monitor sleep position. The apnea–hypopnea index (AHI) was significantly higher in SCI patients than controls (25 ± 15 vs. 9 ± 7, p < 0.001). We found that 63% of SCI patients had moderate-to-severe SDB (AHI ≥ 15) in contrast to 21% of control subjects. Most SCI patients slept predominantly in supine position, but an increased occurrence of events in supine position was only observed for eight patients. This study highlights the problem of SDB in SCI and provides simple cost-effective sleep monitoring tools to facilitate the detection, understanding, and management of SDB in SCI patients.

Topical nasal treatment efficacy on adult obstructive sleep apnea severity: a systematic review and meta-analysis

BACKGROUND

Nasal obstruction is a common complaint in patients with sleep-disordered breathing and obstructive sleep apnea (OSA). Although topical nasal treatments (TNTs) have been shown to reduce nasal resistance and improve nasal obstruction, there is conflicting evidence regarding the role of TNTs in adult OSA. In this systematic review and meta-analysis we aim to evaluate the role of TNTs in adults with OSA. Data sources used included PubMed, Ovid MEDLINE, and Cochrane Central, from January 2001 to July 2019.

METHODS

Inclusion criteria were English-language studies containing original data on TNTs in adults (≥18 years) with OSA (apnea-hypopnea index [AHI] ≥5). Exclusion criteria were case reports, studies without outcome measures, and concurrent non-TNT treatment for OSA. Two investigators independently reviewed all articles and performed quality assessment using validated tools. Meta-analysis and quality assessment were performed.

RESULTS

Of the 2180 abstracts identified, 8 studies met inclusion criteria. TNTs included decongestants (4 of 8 studies), corticosteroids (3 of 8), and antihistamines (1 of 8). Outcome measures included AHI (8 of 8), respiratory distress index (RDI; 1 of 8), oxygen-desaturation index (ODI; 3 of 8), minimum SaO2 (MinSaO₂ ; 4 of 8), nasal resistance (4 of 8), endoscopic sinus surgery (4 of 8 studies) and standardized rhinoconjunctivitis quality of life questionnaire scores (1 of 8 studies). Qualitatively, all studies showed trends toward improving objective and subjective measures of OSA, although the significance of these improvements varied across studies. A meta-analysis was performed in 5 studies, but TNTs did not reveal a significant change in AHI (p > 0.05).

CONCLUSION

TNTs may improve minimum oxygen saturation, ODI, RDI, and subjective/quality-of-life measures. Allergic patients may have more improvement in OSA measures compared with nonallergic patients. Future studies are indicated to accurately determine the efficacy of TNTs.

Impact Of Spinal Cord Injury On Sleep: Current Perspectives

Sleep disorders are commonly encountered in people living with spinal cord injury (SCI). Primary sleep disorders such as sleep-disordered breathing (SDB), sleep-related movement disorders, circadian rhythm sleep-wake disorders, and insomnia disorder are common conditions after SCI but remain under-recognized, underdiagnosed and therefore remain untreated for a majority of patients. Sleep disturbances in people living with SCI are associated with significant impairments of daytime function and quality of life. Previous reviews have described findings related mainly to SDB but have not examined the relationship between other sleep disorders and SCI. This narrative review examines various sleep abnormalities and related functional and physical impairments in people living with SCI. It discusses new evidence pertaining to management, highlights existing limitations in the literature and recommends future directions for research.